The present application relates to a display capable of performing two-dimensional display (planar display) and three-dimensional display (stereoscopic display), and an illumination unit suitably applicable to such a display as a backlight.
Displays capable of performing three-dimensional display include displays in need of wearing special glasses for three-dimensional display and displays without need of the special glasses. In the latter displays, for example, a lenticular lens or a parallax barrier is used to perceive a stereoscopic image with naked eyes. When image information is distributed into right and left eyes by the lenticular lens or the parallax barrier, the right and left eyes see different images, respectively, and as a result, three-dimensional display is achievable.
However, in the case where the above-described parallax barrier is used, resolution in two-dimensional display is reduced. Therefore, Japanese Unexamined Patent Application Publication No. H3-119889 discloses a technique of performing three-dimensional display without impairing resolution in two-dimensional display. In Japanese Unexamined Patent Application Publication No. H3-119889, a parallax barrier is configured of a liquid crystal device, and in three-dimensional display, the liquid crystal device serves as a parallax barrier by forming an opaque section therein. Then, in two-dimensional display, the liquid crystal device does not serve as the parallax barrier by turning an entire surface thereof into a transmission state, and an entire image on a display screen uniformly enters into the right and left eyes.